The present invention relates to a heating apparatus in a reflow system.
In a loading apparatus to print substrates, cream solder is first printed in a predetermined pattern on a surface of a print substrate with a squeegee and a screen mask by means of a printing apparatus. Thereafter, chips that are electric parts are laid thereon, the cream solder is heated to melt and the chips are mounted on the printed substrate.
In such a process, the step for melting the cream solder and loading the chips on the printed substrate is referred to as a xe2x80x9creflowxe2x80x9d apparatus. This is conventionally performed in a heating chamber having a relatively long length of 4 to 6 m.
However, since the heating chamber has a length up to 4 to 6 m in a lateral direction as a whole, a large installation space is required. Also, depending upon a chip, if it is heated for a long period of time at a high temperature, there occurs a problem that it becomes fragile, and, in this case, all the large number of printed substrates simultaneously become the faulty products.
In view of the foregoing defects, an object of the present invention is to provide a heating apparatus that the space needed for heating may be remarkably reduced than that of the conventional case, main heating at a high temperature is applied only to the portion to be soldered in the chips and only a short period of time needs for the heating.
According to the present invention, in order to attain this object, there is provided a heating apparatus in a reflow system, comprising a preheating zone for performing heating at a temperature lower than a melting temperature of cream solder, in which a rope laid between a drive pulley and a driven pulley whose rotation speed may be controlled is vertically disposed within a vertical heat insulating chamber in which an inlet and an outlet are provided in vertical walls on both sides and a feeding conveyor and a receiving/sending conveyor are provided in the inlet and the outlet respectively, support pallets are attached to said rope at a predetermined interval, a plurality of heaters are provided in a central position of the rope in a vertical direction, vanes for introducing heat of the heaters to the support pallets are provided, and fans are disposed above the heaters, and a main heating zone in which an inlet and an outlet are provided in vertical wall on both sides, a pattern mask in which a number of through-holes are formed is fixed horizontally within a heat insulating chamber having an inlet in communication with the outlet of the heat insulating chamber in the preheating zone, a heater is disposed above the pattern mask, fans are disposed above the heater, sleeve bodies having flanges are fitted in necessary through-holes of the pattern mask, one end of a coil spring having the other end engaged with a sleeve body having a flange is fitted with the former sleeve body, a conveyor moving in the horizontal direction is disposed below the sleeve bodies, and heat at a temperature for melting the cream solder by the heater is applied to portions where the cream solder has been coated, through the sleeve bodies and the coil springs by the fans.
Also, in the above-described arrangement, it is possible to provide a shutter moving in a horizontal direction at a predetermined timing to enter below the sleeve bodies for interrupting the application of heated air blow.